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<title>Bitmap Font Generator - Documentation</title>
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<h1>Bitmap Font Generator - Documentation</h1>

<p><a href="../documentation.html">Back to main page</a></p>

<h2>Pixel shader example</h2>

<p>This pixel shader shows how to decode the color from a font texture with characters packed 
into all 4 channels, and each channel using special encoding to store the character with the 
outline. The texture is also allowed to store full 32bit images for some characters.</p>

<pre>
// DirectX 9 pixel shader
float4 PixScene( float4 color : COLOR0,
                 int4   chnl  : TEXCOORD1,
                 float2 tex0  : TEXCOORD0 ) : COLOR0
{
  float4 pixel = tex2D(g_samScene, tex0);
    
  if( dot(vector(1,1,1,1), chnl) )
  {
    float val = dot(pixel, chnl);
		
    pixel.rgb = val > 0.5 ? 2*val-1 : 0;
    pixel.a   = val > 0.5 ? 1 : 2*val;
  }
    
  return pixel * color;
}
</pre>

<p>The chnl texture coordinate is a 4D vector that shows which channel the character should be read 
from. If this is (0,0,0,0) the character is interpreted as a 32 bit image. The texture coordinate 
can be stored in a UBYTE4 type, so it doesn't require much bandwidth when being sent to the video card.</p>



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